This Clinical Research Center has been in operation since October 8, 1962, and detailed project information is submitted in the Annual Report of Center Activities. There are 33 research projects active at this time, including 10 new protocols approved in the current year, RR82-13. These include studies of the altered immune states associated with vaccination, rheumatoid arthritis and cancer. The effects of pancreatic deficiency and bypass operations for obesity on gastrointestinal function are also being investigated. Studies on the mechanism of renal stone formation and on diabetes continue and have been expanded. Drugs used in the treatment of virus infection and cancer are also being evaluated.